Studies on the biology of Ascaris suum infections in mice, isolation of eosinophils and analysis of surface molecules, nature of the elevated IgE response in T cell reconstituted hypothymic nu/nu ("nude") mice to the antigens of the body fluid of Ascaris suum, isolation of phosphorylcholine-containing antigens of Ascaris suum larvae, studies on phsophorylcholine as an inhibitor of antibody responses, isolation and characterization of allergens from Ascaris suum, and the dissection of biological and immunological properties of allergenic molecules administered intranasally to mice.